September is the perfect time to think ahead about next year’s garden. Planting certain vegetables now doesn’t just give you a fall harvest – it actually improves your soil for spring planting.
These veggies add nutrients, break up compacted earth, and protect against erosion during winter months. Your future garden will thank you for this bit of planning ahead!
1. Garlic
Fall-planted garlic builds incredible soil structure while it grows through winter. The long roots reach deep, creating channels for water and breaking up clay.
As a bonus, garlic naturally fights fungal diseases in the soil that could harm spring crops. I’ve noticed earthworms absolutely love the areas where I’ve grown garlic – they multiply like crazy around the roots.
Plant individual cloves about 2 inches deep, pointed end up, and mulch well before frost.
2. Fava Beans
These nitrogen-fixing powerhouses work while you sleep! Fava beans capture nitrogen from the air and store it in nodules on their roots, essentially creating free fertilizer for your spring vegetables.
The sturdy stems also protect soil from winter rain compaction. Many gardeners call favas ‘green manure’ because they’re so effective at enriching poor soil.
Plant seeds 1-2 inches deep and 6 inches apart. Come spring, you can either harvest the beans or chop the plants down and let them decompose right in place.
3. Spinach
Hardy spinach planted in September serves double duty – you’ll get fresh greens in fall and again in early spring when the plants revive. Their roots help prevent soil compaction during winter rains.
The broad leaves of spinach catch falling snow, which slowly melts and gently hydrates the soil instead of running off. My garden beds with spinach always seem more worm-filled come spring.
Sow seeds ½ inch deep in rows or broadcast them. A light frost actually improves spinach flavor by triggering the plant to produce natural sugars.
4. Daikon Radish
Nature’s rototiller! The long tapered roots of daikon radish can penetrate up to 2 feet deep, breaking through compacted subsoil that machines can’t reach.
When left to decompose in place, these massive roots create channels for air, water, and spring plant roots to follow. They also bring up minerals from deep soil layers that would otherwise remain unavailable to shallow-rooted vegetables.
Scatter seeds in September and let them grow until killed by hard frost. No need to harvest unless you want to eat them.
5. Mustard Greens
Spicy mustard plants are soil-cleaning superheroes. Their roots release compounds that suppress harmful nematodes and soil-borne diseases that plague tomatoes and other garden favorites.
This natural process, called biofumigation, happens when you chop the plants down in early spring and turn them into the soil. The decomposing mustard releases beneficial compounds that cleanse the growing area.
Plant mustard seeds in September, and by spring, you’ll have healthier soil plus some zesty greens for your salads if you harvest before flowering.
6. Carrots
Carrots do more than give you a tasty fall harvest — their strong taproots drill down into compacted soil, creating natural air pockets that improve drainage and root growth for spring vegetables.
When left in the ground, even undersized or forgotten carrots eventually decompose, enriching the soil with organic matter. I’ve noticed that beds where carrots overwinter are always softer and easier to work come spring.
Sow seeds about ¼ inch deep in loose soil, keeping rows moist until seedlings sprout. Even if you don’t harvest every carrot, your soil will thank you.
7. Kale
Kale’s deep roots act like soil miners, bringing up calcium, magnesium and other nutrients from lower soil layers. These minerals become available to spring vegetables when kale leaves decompose.
September-planted kale survives most winters, providing harvests through fall and again in early spring before going to seed. The sturdy stems help prevent soil erosion during winter storms.
Many gardeners don’t realize kale is a heavy feeder that leaves soil better than it found it. Plant seedlings 18 inches apart or sow seeds directly in the garden bed.
8. Beets
Beets are quick-growing root crops that help loosen the soil and cycle nutrients from deeper layers up to the topsoil. Their broad leaves act as mini solar panels, capturing energy and feeding soil life when returned as compost or turned under.
Gardeners often overlook how much biomass beet greens add back into the soil. When they decompose, they release valuable minerals like potassium and magnesium, setting the stage for healthier spring crops.
Plant beet seeds ½ inch deep and 2 inches apart. Harvest what you need, and let the rest improve your garden bed naturally.